US4721640A - Flexible magnetic disk sheet - Google Patents
Flexible magnetic disk sheet Download PDFInfo
- Publication number
- US4721640A US4721640A US06/673,640 US67364084A US4721640A US 4721640 A US4721640 A US 4721640A US 67364084 A US67364084 A US 67364084A US 4721640 A US4721640 A US 4721640A
- Authority
- US
- United States
- Prior art keywords
- flexible magnetic
- sheet
- magnetic disc
- compound
- disc sheet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/72—Protective coatings, e.g. anti-static or antifriction
- G11B5/725—Protective coatings, e.g. anti-static or antifriction containing a lubricant, e.g. organic compounds
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/74—Record carriers characterised by the form, e.g. sheet shaped to wrap around a drum
- G11B5/82—Disk carriers
- G11B5/825—Disk carriers flexible discs
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/90—Magnetic feature
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
- Y10T428/24273—Structurally defined web or sheet [e.g., overall dimension, etc.] including aperture
- Y10T428/24322—Composite web or sheet
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/25—Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/25—Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
- Y10T428/254—Polymeric or resinous material
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/25—Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
- Y10T428/259—Silicic material
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/26—Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
- Y10T428/263—Coating layer not in excess of 5 mils thick or equivalent
- Y10T428/264—Up to 3 mils
- Y10T428/265—1 mil or less
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/31504—Composite [nonstructural laminate]
- Y10T428/31551—Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
- Y10T428/31609—Particulate metal or metal compound-containing
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/31504—Composite [nonstructural laminate]
- Y10T428/31855—Of addition polymer from unsaturated monomers
- Y10T428/31935—Ester, halide or nitrile of addition polymer
Definitions
- the present invention relates to an improvement for flexible magnetic disks. More particularly, it relates to a flexible magnetic disk which can be loaded on writing and/or reading apparatus without eccentricity.
- Magnetic recording and playing of a magnetic signal in a flexible magnetic disk comprising a sheet in a jacket, involving connecting a sheet-position determining part of a writing and/or reading apparatus to a central circular hole of the jacket and sheet, and rotating the sheet, is known.
- a space is provided in the magnetic disk which is slightly larger than the sheet, and thus the sheet sometimes moves to an eccentric position in the jacket during use or storage, with the result that the central circular hole of the sheet deviates from the position of a position-determining part (collet) of the apparatus when the disk is loaded on the apparatus, and the sheet may be supported at an eccentric position at the position determining time.
- FIG. 1A and FIG. 1B illustrate this type of flexible magnetic sheet, located in a rectangular jacket having circular open part 1a, with circular flexible magnetic sheet 2 having central circular hole 2a thereof exposed in the afore-mentioned central circular open part 1a, said sheet being stored in the jacket to allow free rotation.
- rotating part 3 (see FIGS. 2-4) of the position-determining part is fitted from under part of the sheet 2, and collet 4 is lowered from upper part of the sheet and is brought into the circular concave part 3a of rotating part 3 as shown in FIG. 2.
- the edge of central circular hole 2a does not always correspond to the position of circular concave part 3a of rotating part 3, and is many times out of proper alignment. If collet 4 is lowered in this state, some part of the portion surrounding the edge of circular hole 2a of the sheet 2 may be pinched between collet 4 and concave part 3a of rotating part 3, such that the sheet rotates eccentrically.
- loading and unloading of the sheet in the reading and/or writing apparatus diminishes the lubricating effect. This may be caused by the lubricating agent being wiped away from the surface portion surrounding the edge of the central hole of a flexible magnetic sheet during loading and unloading of the disc sheet in the apparatus.
- An object of the present invention is to provide a flexible magnetic disc sheet (1) without lose of the beneficial effects of a lubricating agent at high temperature and high humidity and (2) capable of withstanding repeated loading and unloading the disc sheet while maintaining a low friction coefficient between the flexible magnetic disc sheet and the position-determining part without misalignment with the position-determining part.
- the inventors of the present invention have extensively investigated concerning the provision of protective layers, especially those containing a compound polymerizable and curable by exposure to radiation and a lubricating agent, and have found that a very excellent effect can be obtained by a certain combination using a certain type of compound curable by exposure to radiation and a solid lubricating agent.
- a flexible magnetic disk sheet including a central circular hole therein, and having a protective layer on a surface portion surrounding the edge of the central circular hole of the flexible magnetic disk sheet, the protective layer being prepared by coating (a) a compound having an acrylate or a methacrylate bond at the end of at least one of a main chain and a side chain of molecules thereof and (b) a solid lubricating agent, followed by exposing the coated layer to radiation for polymerizing and hardening.
- FIG. 1A is planar view showing an example of a flexible magnetic disk according to the invention.
- FIG. 1B is its cross-section.
- FIG. 2 is a partial cross-sectional view showing the loading of a flexible magnetic disk on a position-determining part of the apparatus.
- FIG. 3 is a partial cross-sectional view showing a case of loading wherein the sheet is supported eccentrically.
- FIG. 4 is a partial cross-sectional view showing a case of loading wherein the sheet is correctly position-determined.
- FIG. 5 is planar view showing a sheet part of an example of the invention.
- FIG. 6 is a cross-sectional view showing in more detail (not to scale) a preferred sheet part according to the invention, wherein protecting layers are formed on both the upper and lower surface portions surrounding the edge of the central circular hole, with a slight clearance on the surface portions between the edges of the protecting layers and the edge of the central circular portion.
- 1 is a jacket
- 1a is an open hole in the jacket
- 2 is a magnetic sheet
- 2a is a central circular hole
- 3 is a position-determining part (ratating part)
- 3a is a circular concave part
- 4 is a postion-determining part (collet)
- 10 is a magnetic sheet
- 10a is the edge of the central circular hole
- 10b and 10b' are surface portions surrounding the edge of the central circular hole
- 11 is a protecting layer
- 12 is a slight clearance between the edges of the protecting layers and the edge of the central circular hole.
- the compound (a) is a compound having an acrylate bond or a methacrylate bond at the end of at least one of a main chain and a side chain of the molecule, and the number of such bonds is generally from 1 to 10, preferably from 1 to 6, and more preferably from 2 to 4, per 1000 units of molecular weight.
- the molecular weight is not particularly limited, but is preferably from 500 to 30,000, and more preferably from 1,000 to 20,000, of an oligomer or a polymer.
- the skeleton of the main chain is preferably a polyester skeleton, a polyurethane skeleton, a polyether skeleton, a polycarbonate skeleton, an epoxy resin skeleton, or a mixed skeleton thereof. Of these, a polyester skeleton and a polyurethane skeleton are more preferred, and a polyurethane skeleton is most preferred. Two or more compounds having different skeletons can be used in combination.
- the radiation used according to this invention includes a low energy radiation ray such as ultraviolet rays, and high energy radiation such as ⁇ -rays, X-rays, and electron beams.
- a low energy radiation ray such as ultraviolet rays
- high energy radiation such as ⁇ -rays, X-rays, and electron beams.
- ultraviolet rays are preferred, because an apparatus for generating ultraviolet rays is simpler.
- aromatic ketones When ultraviolet rays are used as the radiation it is preferred that an aromatic ketone which is a photopolymerization initiator is included. Such aromatic ketones are not particularly limited. Preferred aromatic ketones have a relatively large extinction coefficient at the wavelengths of 254, 313, and 365 nm, at which a mercury lamp commonly used as a source of ultraviolet rays generates bright line spectrum.
- Typical examples are aromatic ketones such as acetophenone, benzophenone, benzoin ethyl ether, benzyl dimethyl ketal, benzyl diethyl ketal, benzoin isobutyl ketone, hydroxydimethyl phenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2,2-diethoxy acetophenone, and Michler's ketone, with benzoin ethyl ether and benzyl dimethyl ketal being preferred.
- aromatic ketones such as acetophenone, benzophenone, benzoin ethyl ether, benzyl dimethyl ketal, benzyl diethyl ketal, benzoin isobutyl ketone, hydroxydimethyl phenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2,2-diethoxy acetophenone, and Michler's ketone, with benzoin
- the content of aromatic ketone is generally from 0.5 to 20 parts by weight, preferably from 2 to 15 parts by weight, and more preferably from 3 to 10 parts by weight, per 100 parts by weight of the compound (a).
- the solid lubricating agents (b) in the present invention are preferably graphite, molybdenum disulfide, tungsten disulfide, boron nitride, graphite fluoride, metal oxides (e.g., a lead monooxide, molybdenum trioxide, silicon dioxide, and the like), silicon nitride, plastic having a molecular weight of from 10 4 and 10 6 , preferably from 10 4 to 5 ⁇ 10 5 (e.g., polytetrafluoroethylene, polyamides such as nylon 6 and nylon 66, polyacetal, polyethylene, polyimide, and the like), and a metal (e.g., lead, copper, zinc, and the like).
- metal oxides e.g., a lead monooxide, molybdenum trioxide, silicon dioxide, and the like
- silicon nitride plastic having a molecular weight of from 10 4 and 10 6 , preferably from 10 4 to 5 ⁇ 10 5 (e.
- the solid lubricating agents generally have an average particle size of from 0.1 to 10 ⁇ , preferably from 0.2 to 5 ⁇ and more preferably from 0.3 to 4 ⁇ . These solid lubricating agents and their properties are described in detail in Solid Lubricant Hand-Book, published by Saiwai Shobo in 1978.
- the content of the compound (b) is from 1 to 50 parts by weight, and preferably from 5 to 10 parts by weight, per 100 parts by weight of compound (a).
- Various organic solvents can be used, if necessary, to facilitate the mixing the compounds (a) and (b) to prepare a coating composition.
- the coating composition containing the aforementioned compounds (a) and (b) can be coated on the surface portion surrounding the edge of the central circular hole of the flexible magnetic disk sheet in a conventional manner.
- the coating thickness after hardening by causing polymerization with exposure to radiation generally ranges from 1 to 50 ⁇ , preferably from 5 to 30 ⁇ , and more preferably from 10 to 20 ⁇ . When the thickness is larger than the above range, it is not favorable owing to the possibility of track-gap. When it is smaller than that range, no sufficient effect results.
- the width of the protecting layer may be varied appropriately depending on the size of the disk sheet.
- the width of the protecting layer generally is from 2 to 5 mm, preferably is from 2.5 to 3.5 mm, and more preferably is from 2.75 to 3.25 mm.
- a slight clearance is provided between the edge of the protecting layer and the edge of the central circular hole; this clearance is generally from 15 to 500 ⁇ , preferably from 30 to 350 ⁇ , and more preferably from 50 to 200 ⁇ .
- FIGS. 5 and 6 illustrate an example of the present invention.
- a protecting layer 11 of the present invention was applied on both sides of the sheet with a clearance 12 of about 100 ⁇ between the edges of the protecting layers and the edge of the central circular hole.
- the width of the protecting layer was 3 mm.
- a protective layer was not provided.
- Coating solutions consisting of the above-mentioned compositions were prepared and applied to the surface portion surrounding the edge of the central circular hole of the flexible magnetic disk sheet so that the amount coated was about 15 g/m 2 , i.e., coating thickness is to be 13 ⁇ . Then, the coated layer was polymerized and hardened by exposing to ultraviolet ray using a high pressure mercury lamp of 80 W/cm.
- the drives used for loading tests on disk drives were YD-280 and 380 made by Y-E Data Co.; JA 751 and 561 made by Matsushita Tsuko Co.); and M-2894 and 4853 made by Mitsubishi Electric Co.
- the magnetic disc sheet of Comparative Example 1 having the same composition as that of the present invention except that a conventionally used lubricating agent was used exhibited a higher friction coefficient in every case and the result of the loading test of the disc sheet with a rotating part was worse under conditions of high temperature and high humidity.
- Comparative Example 2 where no protective layer was provided, exhibited the worst results regarding the friction coefficient and the loading test.
- the protective layer of the present invention provides a low friction coefficient even under high temperature and high humidity conditions, and exhibits excellent result of loading test.
Landscapes
- Paints Or Removers (AREA)
- Magnetic Record Carriers (AREA)
- Lubricants (AREA)
Abstract
Description
______________________________________ Polyurethane acrylate, (trade 100 parts name "M-1100" manufactured by Toa Gosei Chemical Industry Co., Ltd. MoS.sub.2 (trade mark "Molysulfide" 10 parts manufactured by Climax Molybden Co., Ltd.; average particle size in diameter 0.3μ) Benzoin ethyl ether 5 parts ______________________________________
______________________________________ Polyurethane acrylate (trade 100 parts name "M-1100" manufactured by Toa Gosei Chemical Industry Co., Ltd. WS.sub.2 (average particle size 10 parts in diameter: 2μ) Benzoin ethyl ether 5 parts ______________________________________
______________________________________ Polyurethane acrylate (trade 100 parts name "M-1100" manufactured by Toa Gosei Chemical Industry Co., Ltd.) Graphite fluoride (average 10 parts particle size in diameter: 0.5μ) Benzoin ethyl ether 5 parts ______________________________________
______________________________________ Polyurethane acrylate (trade 100 parts name "M-1100" manufactured by Toa Gosei Chemical Industry Co., Ltd.) Butyl stearate 5 parts Benzyl dimethyl ketal 5 parts ______________________________________
TABLE __________________________________________________________________________ 25° C., 80% RH 40° C., 80% RH Friction coefficient Loading test Friction coefficient Loading test (μ) of disc sheet of disc sheet (μ) of disc sheet of disc sheet With With rotat- with rotating With With rotat- with rotating collet ing part part collet ing part part __________________________________________________________________________ Example 1 0.35 0.24 A 0.33 0.28 A Example 2 0.38 0.31 A 0.39 0.32 A Example 3 0.39 0.30 A 0.37 0.33 A Comparative 0.36 0.25 A 0.47 0.37 B Example 1 Comparative 0.55 0.43 B 0.65 0.53 B Example 2 __________________________________________________________________________
Claims (12)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP58-219107 | 1983-11-21 | ||
JP58219107A JPS60111340A (en) | 1983-11-21 | 1983-11-21 | Flexible magnetic disc |
Publications (1)
Publication Number | Publication Date |
---|---|
US4721640A true US4721640A (en) | 1988-01-26 |
Family
ID=16730362
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US06/673,640 Expired - Lifetime US4721640A (en) | 1983-11-21 | 1984-11-21 | Flexible magnetic disk sheet |
Country Status (2)
Country | Link |
---|---|
US (1) | US4721640A (en) |
JP (1) | JPS60111340A (en) |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5085911A (en) * | 1989-06-13 | 1992-02-04 | Fuji Photo Film Co., Ltd. | Flexible magnetic disc with a two layer protective coating which top layer is a ultra violet radiation cured compound with specified elasticity modulus |
US5118525A (en) * | 1989-09-29 | 1992-06-02 | Fuji Photo Film Co., Ltd. | Method for manufacturing magnetic recording medium while preventing damage to same caused by scraping by coating head |
US5279877A (en) * | 1991-09-06 | 1994-01-18 | Tdk Corporation | Magneto optical disc |
US20010055702A1 (en) * | 2000-05-12 | 2001-12-27 | Wang Po Wen | Self-lubricating layer for data storage devices |
US20020187368A1 (en) * | 2001-05-14 | 2002-12-12 | Yuuji Senzaki | Magnetic recording medium and a method of manufacture thereof |
US6589641B1 (en) | 1998-06-04 | 2003-07-08 | Seagate Technology Llc | Thin films of crosslinked fluoropolymer on a carbon substrate |
US6617011B2 (en) | 1999-05-07 | 2003-09-09 | Seagate Technology Llc | Elastomeric lubricants for magnetic recording media |
US6620481B2 (en) * | 2000-07-06 | 2003-09-16 | Fujitsu Limited | Magnetic recording medium, magnetic recording medium manufacture method, and information regeneration apparatus |
US6680079B1 (en) | 2000-06-02 | 2004-01-20 | Seagate Technology Llc | Planarization and corrosion protection of patterned magnetic media |
US20040196592A1 (en) * | 2003-04-04 | 2004-10-07 | Canon Kabushiki Kaisha | Magnetic recording medium, magnetic recording playback device, and information processing device |
US6849304B1 (en) | 2001-03-16 | 2005-02-01 | Seagate Technology Llc | Method of forming lubricant films |
US20070004840A1 (en) * | 2004-05-19 | 2007-01-04 | Texas A&M University | Zinc oxide polymer nanocomposites and methods of producing zinc oxide polymer nanocomposites |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6417277A (en) * | 1987-07-11 | 1989-01-20 | Hitachi Maxell | Discoid recording medium |
Citations (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3466156A (en) * | 1966-12-01 | 1969-09-09 | Ncr Co | Magnetic record members |
US3681225A (en) * | 1969-11-26 | 1972-08-01 | Victor Company Of Japan | Method of making a magnetic disc |
US4239828A (en) * | 1976-03-29 | 1980-12-16 | Minnesota Mining And Manufacturing Company | Self-lubricating magnetic recording diskette |
US4335183A (en) * | 1980-05-12 | 1982-06-15 | Tokyo Magnetic Printing Co., Ltd. | Magnetic recording medium and method of fabricating it |
US4368239A (en) * | 1979-08-06 | 1983-01-11 | Sony Corporation | Magnetic recording medium |
US4387114A (en) * | 1980-11-20 | 1983-06-07 | Verbatim Corporation | Spindle aperture reinforcement for a floppy disk |
US4404247A (en) * | 1982-07-02 | 1983-09-13 | Minnesota Mining And Manufacturing Company | Protective covering for magnetic recording medium |
US4434210A (en) * | 1980-07-03 | 1984-02-28 | Sony Corporation | Magnetic recording medium |
US4486500A (en) * | 1981-03-09 | 1984-12-04 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
US4523246A (en) * | 1983-03-29 | 1985-06-11 | Fuji Photo Film Co., Ltd. | Flexible magnetic disk |
US4539220A (en) * | 1983-09-23 | 1985-09-03 | Verbatim Corporation | Method of manufacturing reinforced flexible disks |
US4578299A (en) * | 1983-07-21 | 1986-03-25 | Fuji Photo Film Co., Ltd. | Flexible magnetic disk sheet |
US4581270A (en) * | 1983-07-18 | 1986-04-08 | Fuji Photo Film Co., Ltd. | Flexible magnetic disk |
-
1983
- 1983-11-21 JP JP58219107A patent/JPS60111340A/en active Granted
-
1984
- 1984-11-21 US US06/673,640 patent/US4721640A/en not_active Expired - Lifetime
Patent Citations (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3466156A (en) * | 1966-12-01 | 1969-09-09 | Ncr Co | Magnetic record members |
US3681225A (en) * | 1969-11-26 | 1972-08-01 | Victor Company Of Japan | Method of making a magnetic disc |
US4239828A (en) * | 1976-03-29 | 1980-12-16 | Minnesota Mining And Manufacturing Company | Self-lubricating magnetic recording diskette |
US4368239A (en) * | 1979-08-06 | 1983-01-11 | Sony Corporation | Magnetic recording medium |
US4335183A (en) * | 1980-05-12 | 1982-06-15 | Tokyo Magnetic Printing Co., Ltd. | Magnetic recording medium and method of fabricating it |
US4434210A (en) * | 1980-07-03 | 1984-02-28 | Sony Corporation | Magnetic recording medium |
US4387114A (en) * | 1980-11-20 | 1983-06-07 | Verbatim Corporation | Spindle aperture reinforcement for a floppy disk |
US4486500A (en) * | 1981-03-09 | 1984-12-04 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
US4404247A (en) * | 1982-07-02 | 1983-09-13 | Minnesota Mining And Manufacturing Company | Protective covering for magnetic recording medium |
US4523246A (en) * | 1983-03-29 | 1985-06-11 | Fuji Photo Film Co., Ltd. | Flexible magnetic disk |
US4581270A (en) * | 1983-07-18 | 1986-04-08 | Fuji Photo Film Co., Ltd. | Flexible magnetic disk |
US4578299A (en) * | 1983-07-21 | 1986-03-25 | Fuji Photo Film Co., Ltd. | Flexible magnetic disk sheet |
US4539220A (en) * | 1983-09-23 | 1985-09-03 | Verbatim Corporation | Method of manufacturing reinforced flexible disks |
Cited By (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5085911A (en) * | 1989-06-13 | 1992-02-04 | Fuji Photo Film Co., Ltd. | Flexible magnetic disc with a two layer protective coating which top layer is a ultra violet radiation cured compound with specified elasticity modulus |
US5118525A (en) * | 1989-09-29 | 1992-06-02 | Fuji Photo Film Co., Ltd. | Method for manufacturing magnetic recording medium while preventing damage to same caused by scraping by coating head |
US5279877A (en) * | 1991-09-06 | 1994-01-18 | Tdk Corporation | Magneto optical disc |
US6589641B1 (en) | 1998-06-04 | 2003-07-08 | Seagate Technology Llc | Thin films of crosslinked fluoropolymer on a carbon substrate |
US20040048053A1 (en) * | 1999-05-07 | 2004-03-11 | Seagate Technology Llc | Elastomeric lubricants for magnetic recording media |
US6861102B2 (en) | 1999-05-07 | 2005-03-01 | Seagate Technology Llc | Elastomeric lubricants for magnetic recording media |
US6617011B2 (en) | 1999-05-07 | 2003-09-09 | Seagate Technology Llc | Elastomeric lubricants for magnetic recording media |
US20010055702A1 (en) * | 2000-05-12 | 2001-12-27 | Wang Po Wen | Self-lubricating layer for data storage devices |
US6677105B2 (en) * | 2000-05-12 | 2004-01-13 | Toda Kogyo Corporation | Self-lubricating layer for data storage devices |
US6680079B1 (en) | 2000-06-02 | 2004-01-20 | Seagate Technology Llc | Planarization and corrosion protection of patterned magnetic media |
US20040101715A1 (en) * | 2000-06-02 | 2004-05-27 | Seagate Technology Llc | Planarization and corrosion protection of patterned magnetic media |
US6821627B2 (en) | 2000-06-02 | 2004-11-23 | Seagate Technology Llc | Planarization and corrosion protection of patterned magnetic media |
US6620481B2 (en) * | 2000-07-06 | 2003-09-16 | Fujitsu Limited | Magnetic recording medium, magnetic recording medium manufacture method, and information regeneration apparatus |
US6849304B1 (en) | 2001-03-16 | 2005-02-01 | Seagate Technology Llc | Method of forming lubricant films |
US20020187368A1 (en) * | 2001-05-14 | 2002-12-12 | Yuuji Senzaki | Magnetic recording medium and a method of manufacture thereof |
US20040196592A1 (en) * | 2003-04-04 | 2004-10-07 | Canon Kabushiki Kaisha | Magnetic recording medium, magnetic recording playback device, and information processing device |
US7167342B2 (en) * | 2003-04-04 | 2007-01-23 | Canon Kabushiki Kaisha | Magnetic recording medium, magnetic recording playback device, and information processing device |
US20070004840A1 (en) * | 2004-05-19 | 2007-01-04 | Texas A&M University | Zinc oxide polymer nanocomposites and methods of producing zinc oxide polymer nanocomposites |
Also Published As
Publication number | Publication date |
---|---|
JPH053658B2 (en) | 1993-01-18 |
JPS60111340A (en) | 1985-06-17 |
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